Some of nicotinic acid derivatives represented by the after-mentioned formula (I) and compounds represented by the after-mentioned formula (II) as starting materials for the production thereof, are included in the compounds represented by the formula (I) disclosed in EP-494770A. However, in such publication, there is no specific disclosure of the respective compounds or a method for their production. On the other hand, some of compounds represented by the after-mentioned formula (III) are disclosed as compounds of the formula (VI) in JP-A-6-41116 at pages 41 and 58 to 69.
Patent Document 1: EP-494770A
Patent Document 2: JP-A-6-41116